ABSTRACT: Differential regulation of extracellular matrix constituents in myocardial remodeling with and without heart failure following pressure overload
Project description:Background Chronic sustained pressure overload induces cardiac remodeling, which often leads to heart failure. Cardiac macrophages (cMacs) are heterogeneous cell populations, and their elimination has been shown to exacerbate pressure overload-induced heart failure. CD163, a macrophage-specific scavenger receptor expressed in a subset of cMacs, has been linked to cardiovascular events through its serum soluble form. This study aimed to elucidate the functional role of the CD163+ cMacs subset in pressure overload-induced heart failure. Methods Transverse aortic constriction (TAC) was performed on wild-type and CD163-deficient (Cd163-/-) mice to investigate the role of CD163 in pressure overload-induced cardiac remodeling and heart failure. Echocardiography was used to assess heart structure and function. Transcriptomic analysis and transmission electron microscopy were employed to observe mitochondrial structure in cardiomyocytes. Flow cytometry was used to quantify cMacs and cytokine-expressing cMacs in the heart. Additionally, serum samples from hypertensive patients with and without heart failure were analyzed to explore the relationship between CD163 and heart failure. Results TAC-induced left ventricular systolic dysfunction, including reduced ejection fraction and fractional shortening, was significantly aggravated in Cd163-/- mice post-surgery. Genes differentially expressed due to CD163 deficiency were enriched in pathways related to mitochondrial bioenergetics and homeostasis. Transmission electron microscopy revealed an increase in dysfunctional mitochondria in cardiomyocytes of Cd163-/- mice post-TAC. Additionally, decreased serum interleukin (IL)-10 levels and reduced IL-10 expression in cMacs were observed in Cd163-/- mice post-TAC. IL-10 supplementation significantly reversed TAC-induced reductions in left ventricular systolic function and improved mitochondrial bioenergetics and homeostasis in Cd163-/- mice. Conclusions The protective functions of CD163 in cMacs are associated with IL-10 expression during pressure overload-induced heart failure.
Project description:To investiage the ability of positve inotropism from myocardial Rad reduction we induced Rad knockout after onset of pressure overload to reverse or compensate progression of heart failure
Project description:Heart failure is a complex clinical syndrome characterized by insufficient cardiac function. It has been characterized that heart resident and infiltrated macrophages play important roles in the cardiac remodeling in response to cardiac pressure overload, however, role of T cells has not been well characterized. Here we show that CD8+T cell depletion resulted in the late stage heart protection, but induced cardioprotective hypertrophy at an early stage of heart failure caused by cardiac pressure overload. Single cell RNA sequencing analysis revealed that cardioprotective hypertrophy was characterized by an expression of mitochondrial genes and growth factor receptors genes. CD8+T cells regulated the conversion of cardiac-resident macrophages as well as infiltrated macrophages to cardioprotective macrophages which express growth factor genes including Areg, Osm and Csf1 at the early phase of cardiac pressure overload, which are essential for the myocardial adaptive response. Our results demonstrate a dynamic interplay between cardiac CD8+T cells and macrophages that is necessary for adaptation to cardiac stress, and they highlight the homeostatic functions of tissue macrophages.
Project description:Chronic pressure overload initiates a series of molecular alterations in the human heart that predate macroscopic organ-level remodeling and downstream heart failure (HF). We hypothesized that integrating easily accessible circulating mediators (proteome) with their expression in the heart (transcriptome) may prioritize targets for study in human pressure overload. Among individuals with severe aortic stenosis (AS)—a pressure overload state—we measured the circulating proteome (Olink) and examined associations with myocardial structure/function (N=519), cardiac MRI-based tissue fibrosis (N=145), and outcomes in AS (N=802). We constructed proteomic signatures of cardiac remodeling and tested their association with HF in the UK Biobank (N=36,668). For proteo-transcriptional integration, we examined a "remodeling proteome” prioritized by proteome-phenotype relations at the transcriptional level via single nuclear RNA-sequencing (snRNA-seq) in 20 human hearts (11 with AS at the time of surgical aortic valve replacement [AVR] and 9 donor hearts not used for transplantation). We identified three principal components of myocardial remodeling (across 12 echocardiographic measures in 503 patients with AS) loaded on cardiac morphology, systolic, and diastolic function traits. Proteins associated with these components (the “remodeling proteome”) specified both known and novel mediators of fibrosis, hypertrophy, and oxidative stress, several of which were associated with interstitial fibrosis by cardiac MRI. Proteomic signatures of remodeling were strongly linked to mortality (AS cohort and UK Biobank) and incident HF (UK Biobank). At a myocardial level, we observed broad differential expression of genes encoding the remodeling proteome between AS and donor hearts, featuring convergent fibrosis pathways (WNT9A, ITGA6, AGRN, CRIM1, SEMA4C, LAYN, PTX3, HMOX1) and metabolic-inflammatory signaling (ENPP2/ATX, TNF), among others. Differential expression of proteo-transcriptionally prioritized genes was prominent in fibroblasts, cardiomyocytes, and endothelial cells. Proteo-transcriptional prioritization in human pressure overload hearts identifies both known and novel targets that are mechanistically relevant to HF pathogenesis. Future integrative studies to index circulating biomarkers over time to myocardial tissue level is warranted to inform pathways of HF progression.
Project description:Atherosclerosis and pressure overload are major risk factors for the development of heart failure in patients. Cardiac hypertrophy often precedes the development of heart failure. However, underlying mechanisms are incompletely understood. To investigate pathomechanisms underlying the transition from cardiac hypertrophy to heart failure we used experimental models of atherosclerosis- and pressure overload-induced cardiac hypertrophy and failure, i.e. apolipoprotein E (apoE)-deficient mice, which develop heart failure at an age of 18 months, and non-transgenic C57BL/6J (B6) mice with heart failure triggered by 6 months of pressure overload induced by abdominal aortic constriction (AAC). The development of heart failure was monitored by echocardiography, invasive hemodynamics and histology. The microarray gene expression study of cardiac genes was performed with heart tissue from failing hearts relative to hypertrophic and healthy heart tissue, respectively. The microarray study revealed that the onset of heart failure was accompanied by a strong up-regulation of cardiac lipid metabolism genes involved in fat synthesis, storage and oxidation. Microarray gene expression profiling was performed with heart tissue isolated from (i) 18 month-old apoE-deficient mice relative to age-matched non-transgenic C57BL/6J (B6) mice, (ii) 6 month-old apoE-deficient mice with 2 months of chronic pressure overload induced by abdominal aortic constriction (AAC) relative to sham-operated apoE-deficient mice and nontransgenic B6 mice, (iii) 10 month-old B6 mice with 6 months of AAC relative to sham-operated B6 mice, and (iv) 5 month-old B6 mice with 1 month of AAC relative to age-matched B6 mice.
Project description:To identify the role of mRNA on the mouse heart during pressure overload induced heart failure, we have employed high-throughput sequencing to detect mRNA expression. Samples were collected from the sham group and the pressure overload groups (2, 4 and 8 weeks after TAC), with 2 samples per group. The candidate mRNA that may affect the process of heart failure was screened by comparing the pressure overload groups and the sham group.
Project description:In humans, cardiac hypertrophy is the principal risk factor for the development of overt heart failure and sudden cardiac death from lethal arrhythmias. Although aberrant reactivation of fetal² gene programs is intricately linked to maladaptive hypertrophy of postnatal cardiomyocytes, loss of cardiac function and heart failure, the transcription factors driving these gene programs remain ill defined. We report that the basic helix-loop-helix (bHLH) transcription factor dHAND/Hand2 is re-expressed in the mammalian postnatal myocardium in response to stress signaling. Interestingly, mutant mice overexpressing Hand2 in otherwise healthy ventricular myocytes developed a phenotype of pathological hypertrophy. In contrast, conditional gene-targeted Hand2 mice demonstrated a marked resistance to pressure overload-induced hypertrophy, fibrosis, ventricular dysfunction and induction of a fetal gene program. These data suggest a critical role for the Hand2 transcription factor during hypertrophic remodeling and heart failure. To gain more mechanistically insight in the processes underlying heart failure, we here identified Hand2 target genes by microarray gene expression profiling. RNA samples were collected 4 weeks after sham or TAC surgery (to induce pressure overload) of both tamoxifen-treated Hand2f/f (WT) and MCM-Hand2f/f (KO) mice.
Project description:To identify the role of circRNA on the mouse heart during pressure overload induced heart failure, we have employed circRNA microarray expression profiling as a discovery platform to detect circRNA expression. Samples were collected from the sham group and the pressure overload groups (2, 4 and 8 weeks after TAC), with 2 samples per group. The candidate circRNA that may affect the process of heart failure was screened by comparing the pressure overload groups and the sham group.
Project description:Semaglutide, a glucagon-like peptide-1 receptor agonist, is clinically used as a glucose-lowering and weight loss medication due to its effects on energy metabolism. In heart failure, energy production is impaired due to altered mitochondrial function and increased glycolysis. However, the impact of semaglutide on cardiomyocyte metabolism under pressure overload remains unclear. Here we demonstrate that semaglutide improves cardiac function and reduces hypertrophy and fibrosis in a mouse model of pressure overload-induced heart failure. Semaglutide preserves mitochondrial structure and function under chronic stress. Metabolomics reveals that semaglutide reduces mitochondrial damage, lipid accumulation, and ATP deficiency by promoting pyruvate entry into the tricarboxylic acid cycle and increasing fatty acid oxidation. Transcriptional analysis shows that semaglutide regulates myocardial energy metabolism through the Creb5/NR4a1 axis in the PI3K/AKT pathway, reducing NR4a1 expression and its translocation to mitochondria. NR4a1 knockdown ameliorates mitochondrial dysfunction and abnormal glucose and lipid metabolism in the heart. These findings suggest that semaglutide may be a therapeutic agent for improving cardiac remodeling by modulating energy metabolism.
Project description:Atherosclerosis and pressure overload are major risk factors for the development of heart failure in patients. Cardiac hypertrophy often precedes the development of heart failure. However, underlying mechanisms are incompletely understood. To investigate pathomechanisms underlying the transition from cardiac hypertrophy to heart failure we used experimental models of atherosclerosis- and pressure overload-induced cardiac hypertrophy and failure, i.e. apolipoprotein E (apoE)-deficient mice, which develop heart failure at an age of 18 months, and non-transgenic C57BL/6J (B6) mice with heart failure triggered by 6 months of pressure overload induced by abdominal aortic constriction (AAC). The development of heart failure was monitored by echocardiography, invasive hemodynamics and histology. The microarray gene expression study of cardiac genes was performed with heart tissue from failing hearts relative to hypertrophic and healthy heart tissue, respectively. The microarray study revealed that the onset of heart failure was accompanied by a strong up-regulation of cardiac lipid metabolism genes involved in fat synthesis, storage and oxidation.